In the case that electronic apparatuses such as computers, displays, and mobile phones, do not radiate heat generated from the inside of the electronic apparatuses, screen image retention, system failure, or shortening of product life may be caused due to excessively accumulated heat, and in severe cases explosion or fire may be caused.
In particular, portable terminals such as mobile phones (or smart phones) essentially require miniaturization and weight reduction in order to maximize portability and convenience of users, and are configured by mounting more and more integrated components in a small space to secure high performance. Accordingly, components used in the portable terminal may cause a higher heating temperature due to the high performance of the portable terminal, and the elevated temperature of the heat affects the adjacent components to degrade the performance of the portable terminal.
Meanwhile, a portable terminal such as a mobile phone is frequently used at a state where the mobile phone contacts a human face in use, and consequently the heat generated in the portable terminal is transferred to the skin of a user, to thereby cause proteins of the skin of the user to be damaged, that is, to thereby cause a problem of inflicting low-temperature burns on the user. Accordingly, the heat delivered to the outside of the mobile terminal needs to be lowered down to a certain temperature or lower.
In order to solve such a problem caused by heat generation of the portable terminal, a variety of insulating materials are employed, but an optimal insulation material whose thickness is thin and whose insulation and heat dissipation performance are excellent has not yet developed. Accordingly, a variety of researches and technology developments are urgently required.
Graphite is widely used as the heat radiation material. However, graphite is very expensive, and has excellent heat radiation performance, but has poor insulation performance. As a result, it is limited to employ graphite. Since no materials that may replace the graphite have been developed yet, although manufacturers know that graphite may cause a problem, graphite is still used.
Meanwhile, Korea Patent Registration No. 10-1134880 discloses a technology of preventing heat generated from a mobile terminal from being delivered to a user's face through a liquid crystal display (LCD) panel in which an insulation film is disposed on the front surface of the LCD panel. However, this insulation film is a low emissivity film that allows a transmittance of visible light at maximum and blocks passage of heat, and is attached on the front surface of the LCD panel. Such a low emissivity insulation film reaches the limit in insulating high temperature heat generated from components built in a portable terminal, and thus cannot solve problems caused by heat generated from high performance mobile terminals, in recent years.